141 research outputs found

    Segmentation-assisted detection of dirt impairments in archived film sequences

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    A novel segmentation-assisted method for film dirt detection is proposed. We exploit the fact that film dirt manifests in the spatial domain as a cluster of connected pixels whose intensity differs substantially from that of its neighborhood and we employ a segmentation-based approach to identify this type of structure. A key feature of our approach is the computation of a measure of confidence attached to detected dirt regions which can be utilized for performance fine tuning. Another important feature of our algorithm is the avoidance of the computational complexity associated with motion estimation. Our experimental framework benefits from the availability of manually derived as well as objective ground truth data obtained using infrared scanning. Our results demonstrate that the proposed method compares favorably with standard spatial, temporal and multistage median filtering approaches and provides efficient and robust detection for a wide variety of test material

    Detection of dirt impairments from archived film sequences : survey and evaluations

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    Film dirt is the most commonly encountered artifact in archive restoration applications. Since dirt usually appears as a temporally impulsive event, motion-compensated interframe processing is widely applied for its detection. However, motion-compensated prediction requires a high degree of complexity and can be unreliable when motion estimation fails. Consequently, many techniques using spatial or spatiotemporal filtering without motion were also been proposed as alternatives. A comprehensive survey and evaluation of existing methods is presented, in which both qualitative and quantitative performances are compared in terms of accuracy, robustness, and complexity. After analyzing these algorithms and identifying their limitations, we conclude with guidance in choosing from these algorithms and promising directions for future research

    Sur la Restauration et l'Edition de Vidéo : Détection de Rayures et Inpainting de ScÚnes Complexes

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    The inevitable degradation of visual content such as images and films leads to the goal ofimage and video restoration. In this thesis, we look at two specific restoration problems : the detection ofline scratches in old films and the automatic completion of videos, or video inpainting as it is also known.Line scratches are caused when the film physically rubs against a mechanical part. This origin resultsin the specific characteristics of the defect, such as verticality and temporal persistence. We propose adetection algorithm based on the statistical approach known as a contrario methods. We also proposea temporal filtering step to remove false alarms present in the first detection step. Comparisons withprevious work show improved recall and precision, and robustness with respect to the presence of noiseand clutter in the film.The second part of the thesis concerns video inpainting. We propose an algorithm based on theminimisation of a patch-based functional of the video content. In this framework, we address the followingproblems : extremely high execution times, the correct handling of textures in the video and inpaintingwith moving cameras. We also address some convergence issues in a very simplified inpainting context.La degradation inĂ©vitable des contenus visuels (images, films) conduit nĂ©cessairementĂ  la tĂąche de la restauration des images et des vidĂ©os. Dans cetre thĂšse, nous nous intĂ©resserons Ă deux sous-problĂšmes de restauration : la dĂ©tection des rayures dans les vieux films, et le remplissageautomatique des vidĂ©os (“inpainting vidĂ©o en anglais).En gĂ©nĂ©ral, les rayures sont dues aux frottements de la pellicule du film avec un objet lors de laprojection du film. Les origines physiques de ce dĂ©faut lui donnent des caractĂ©ristiques trĂšs particuliers.Les rayures sont des lignes plus ou moins verticales qui peuvent ĂȘtre blanches ou noires (ou parfois encouleur) et qui sont temporellement persistantes, c’est-Ă -dire qu’elles ont une position qui est continuedans le temps. Afin de dĂ©tecter ces dĂ©fauts, nous proposons d’abord un algorithme de dĂ©tection basĂ©sur un ensemble d’approches statistiques appelĂ©es les mĂ©thodes a contrario. Cet algorithme fournitune dĂ©tection prĂ©cise et robuste aux bruits et aux textures prĂ©sentes dans l’image. Nous proposonsĂ©galement une Ă©tape de filtrage temporel afin d’écarter les fausses alarmes de la premiĂšre Ă©tape dedĂ©tection. Celle-ci amĂ©liore la prĂ©cision de l’algorithme en analysant le mouvement des dĂ©tections spatiales.L’ensemble de l’algorithme (dĂ©tection spatiale et filtrage temporel) est comparĂ© Ă  des approchesde la littĂ©rature et montre un rappel et une prĂ©cision grandement amĂ©liorĂ©s.La deuxiĂšme partie de cette thĂšse est consacrĂ©e Ă  l’inpainting vidĂ©o. Le but ici est de remplirune rĂ©gion d’une vidĂ©o avec un contenu qui semble visuellement cohĂ©rent et convaincant. Il existeune plĂ©thore de mĂ©thodes qui traite ce problĂšme dans le cas des images. La littĂ©rature dans le casdes vidĂ©os est plus restreinte, notamment car le temps d’exĂ©cution reprĂ©sente un vĂ©ritable obstacle.Nous proposons un algorithme d’inpainting vidĂ©o qui vise l’optimisation d’une fonctionnelle d’énergiequi intĂšgre la notion de patchs, c’est-Ă -dire des petits cubes de contenu vidĂ©o. Nous traitons d’abord leprobl’‘eme du temps d’exĂ©cution avant d’attaquer celui de l’inpainting satisfaisant des textures dans lesvidĂ©os. Nous traitons Ă©galement le cas des vidĂ©os dont le fond est en mouvement ou qui ont Ă©tĂ© prisesavec des camĂ©ras en mouvement. Enfin, nous nous intĂ©ressons Ă  certaines questions de convergencede l’algorithme dans des cas trĂšs simplifiĂ©s

    Digital tools in media studies: analysis and research. An overview

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    Digital tools are increasingly used in media studies, opening up new perspectives for research and analysis, while creating new problems at the same time. In this volume, international media scholars and computer scientists present their projects, varying from powerful film-historical databases to automatic video analysis software, discussing their application of digital tools and reporting on their results. This book is the first publication of its kind and a helpful guide to both media scholars and computer scientists who intend to use digital tools in their research, providing information on applications, standards, and problems

    Digital Tools in Media Studies

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    Digital tools are increasingly used in media studies, opening up new perspectives for research and analysis, while creating new problems at the same time. In this volume, international media scholars and computer scientists present their projects, varying from powerful film-historical databases to automatic video analysis software, discussing their application of digital tools and reporting on their results. This book is the first publication of its kind and a helpful guide to both media scholars and computer scientists who intend to use digital tools in their research, providing information on applications, standards, and problems

    Fine Art Pattern Extraction and Recognition

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    This is a reprint of articles from the Special Issue published online in the open access journal Journal of Imaging (ISSN 2313-433X) (available at: https://www.mdpi.com/journal/jimaging/special issues/faper2020)

    Visual and Camera Sensors

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    This book includes 13 papers published in Special Issue ("Visual and Camera Sensors") of the journal Sensors. The goal of this Special Issue was to invite high-quality, state-of-the-art research papers dealing with challenging issues in visual and camera sensors

    Remote Sensing and Geosciences for Archaeology

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    This book collects more than 20 papers, written by renowned experts and scientists from across the globe, that showcase the state-of-the-art and forefront research in archaeological remote sensing and the use of geoscientific techniques to investigate archaeological records and cultural heritage. Very high resolution satellite images from optical and radar space-borne sensors, airborne multi-spectral images, ground penetrating radar, terrestrial laser scanning, 3D modelling, Geographyc Information Systems (GIS) are among the techniques used in the archaeological studies published in this book. The reader can learn how to use these instruments and sensors, also in combination, to investigate cultural landscapes, discover new sites, reconstruct paleo-landscapes, augment the knowledge of monuments, and assess the condition of heritage at risk. Case studies scattered across Europe, Asia and America are presented: from the World UNESCO World Heritage Site of Lines and Geoglyphs of Nasca and Palpa to heritage under threat in the Middle East and North Africa, from coastal heritage in the intertidal flats of the German North Sea to Early and Neolithic settlements in Thessaly. Beginners will learn robust research methodologies and take inspiration; mature scholars will for sure derive inputs for new research and applications
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